Tweak the leak task handling and resetConnection() handling for small performance gains in the *nominal* case. Possibly slower in edge-cases (but who cares).

hikaricp-java6/src/main/java/com/zaxxer/hikari/pool/HikariPool.java

@@ -48,6 +48,7 @@ import com.zaxxer.hikari.metrics.IMetricsTracker.MetricsContext;
 import com.zaxxer.hikari.metrics.MetricsFactory;
 import com.zaxxer.hikari.metrics.MetricsTracker;
 import com.zaxxer.hikari.proxy.IHikariConnectionProxy;
+import com.zaxxer.hikari.proxy.LeakTask;
 import com.zaxxer.hikari.proxy.ProxyFactory;
 import com.zaxxer.hikari.util.ConcurrentBag;
 import com.zaxxer.hikari.util.ConcurrentBag.IBagStateListener;
@@ -64,12 +65,13 @@ import com.zaxxer.hikari.util.PropertyBeanSetter;
  */
 public final class HikariPool implements HikariPoolMBean, IBagStateListener
 {
-   private static final Logger LOGGER = LoggerFactory.getLogger(HikariPool.class);
+   private static final Logger LOGGER;
+   private static final LeakTask NO_LEAK;
 
-   public int transactionIsolation;
    public final String catalog;
    public final boolean isAutoCommit;
    public final boolean isReadOnly;
+   public int transactionIsolation;
 
    private final DataSource dataSource;
 
@@ -95,6 +97,14 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
    private volatile long connectionTimeout;
    private volatile boolean isShutdown;
 
+   // static initializer
+   static {
+      LOGGER = LoggerFactory.getLogger(HikariPool.class);
+      NO_LEAK = new LeakTask() {
+         public void cancel() {};
+      };
+   }
+
    /**
     * Construct a HikariPool with the specified configuration.
     *
@@ -142,8 +152,8 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
          HikariMBeanElf.registerMBeans(configuration, this);
       }
 
-      addConnectionExecutor = createThreadPoolExecutor(configuration.getMaximumPoolSize(), "HikariCP connection filler", configuration.getThreadFactory());
+      addConnectionExecutor = createThreadPoolExecutor(configuration.getMaximumPoolSize(), "HikariCP connection filler (pool " + configuration.getPoolName() + ")", configuration.getThreadFactory());
-      closeConnectionExecutor = createThreadPoolExecutor(configuration.getMaximumPoolSize(), "HikariCP connection closer", configuration.getThreadFactory());
+      closeConnectionExecutor = createThreadPoolExecutor(configuration.getMaximumPoolSize(), "HikariCP connection closer (pool " + configuration.getPoolName() + ")", configuration.getThreadFactory());
 
       fillPool();
 
@@ -181,11 +191,9 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
                continue;
             }
 
-            final IHikariConnectionProxy proxyConnection = ProxyFactory.getProxyConnection(this, bagEntry);
+            LeakTask leakTask = (leakDetectionThreshold == 0) ? NO_LEAK : new LeakTask(leakDetectionThreshold, houseKeepingExecutorService);
-
+            
-            if (leakDetectionThreshold != 0) {
+            final IHikariConnectionProxy proxyConnection = ProxyFactory.getProxyConnection(this, bagEntry, leakTask);
-               proxyConnection.captureStack(leakDetectionThreshold, houseKeepingExecutorService);
-            }
 
             if (isRecordMetrics) {
                bagEntry.lastOpenTime = now;

hikaricp-java6/src/main/java/com/zaxxer/hikari/proxy/ConnectionProxy.java

@@ -24,8 +24,6 @@ import java.sql.Statement;
 import java.sql.Wrapper;
 import java.util.HashSet;
 import java.util.Set;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -41,27 +39,28 @@ import com.zaxxer.hikari.util.FastList;
  */
 public abstract class ConnectionProxy implements IHikariConnectionProxy
 {
-   private static final Logger LOGGER = LoggerFactory.getLogger(ConnectionProxy.class);
+   private static final Logger LOGGER;
-
    private static final Set<String> SQL_ERRORS;
 
    protected final Connection delegate;
 
    private final HikariPool parentPool;
    private final PoolBagEntry bagEntry;
-
+   private final FastList<Statement> openStatements;
+   private final LeakTask leakTask;
+   
    private boolean forceClose;
+   private boolean isAnythingDirty;
    private boolean isAutoCommitDirty;
    private boolean isCatalogDirty;
    private boolean isClosed;
    private boolean isReadOnlyDirty;
    private boolean isTransactionIsolationDirty;
 
-   private FastList<Statement> openStatements;
-   private LeakTask leakTask;
-
    // static initializer
    static {
+      LOGGER = LoggerFactory.getLogger(ConnectionProxy.class);
+
       SQL_ERRORS = new HashSet<String>();
       SQL_ERRORS.add("57P01"); // ADMIN SHUTDOWN
       SQL_ERRORS.add("57P02"); // CRASH SHUTDOWN
@@ -71,10 +70,11 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       SQL_ERRORS.add("JZ0C1"); // Sybase disconnect error
    }
 
-   protected ConnectionProxy(final HikariPool pool, final PoolBagEntry bagEntry) {
+   protected ConnectionProxy(final HikariPool pool, final PoolBagEntry bagEntry, final LeakTask leakTask) {
       this.parentPool = pool;
       this.bagEntry = bagEntry;
       this.delegate = bagEntry.connection;
+      this.leakTask = leakTask;
 
       this.openStatements = new FastList<Statement>(Statement.class, 16);
    }
@@ -96,18 +96,6 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       return bagEntry;
    }
 
-   /** {@inheritDoc} */
-   @Override
-   public final void captureStack(long leakDetectionThreshold, ScheduledExecutorService executorService)
-   {
-      StackTraceElement[] trace = Thread.currentThread().getStackTrace();
-      StackTraceElement[] leakTrace = new StackTraceElement[trace.length - 4];
-      System.arraycopy(trace, 4, leakTrace, 0, leakTrace.length);
-
-      leakTask = new LeakTask(leakTrace, leakDetectionThreshold);
-      executorService.schedule(leakTask, leakDetectionThreshold, TimeUnit.MILLISECONDS);
-   }
-
    /** {@inheritDoc} */
    @Override
    public final SQLException checkException(SQLException sqle)
@@ -184,8 +172,6 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       if (isCatalogDirty && parentPool.catalog != null) {
          delegate.setCatalog(parentPool.catalog);
       }
-
-      delegate.clearWarnings();
    }
 
    // **********************************************************************
@@ -199,10 +185,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       if (!isClosed) {
          isClosed = true;
 
-         if (leakTask != null) {
+         leakTask.cancel();
-            leakTask.cancel();
-            leakTask = null;
-         }
 
          try {
             final int size = openStatements.size();
@@ -216,13 +199,17 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
                   }
                }
 
-               openStatements = null;
+               openStatements.clear();
+            }
+
+            if (isAnythingDirty) {
+               resetConnectionState();
             }
 
-            resetConnectionState();
+            delegate.clearWarnings();
          }
          catch (SQLException e) {
-            checkException(e);
+            throw checkException(e);
          }
          finally {
             parentPool.releaseConnection(bagEntry, forceClose);
@@ -432,6 +419,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setAutoCommit(autoCommit);
+         isAnythingDirty = true;
          isAutoCommitDirty = (autoCommit != parentPool.isAutoCommit);
       }
       catch (SQLException e) {
@@ -446,6 +434,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setReadOnly(readOnly);
+         isAnythingDirty = true;
          isReadOnlyDirty = (readOnly != parentPool.isReadOnly);
       }
       catch (SQLException e) {
@@ -460,6 +449,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setTransactionIsolation(level);
+         isAnythingDirty = true;
          isTransactionIsolationDirty = (level != parentPool.transactionIsolation);
       }
       catch (SQLException e) {
@@ -473,6 +463,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setCatalog(catalog);
+         isAnythingDirty = true;
          isCatalogDirty = (catalog != null && !catalog.equals(parentPool.catalog)) || (catalog == null && parentPool.catalog != null);
       }
       catch (SQLException e) {

hikaricp-java6/src/main/java/com/zaxxer/hikari/proxy/IHikariConnectionProxy.java

@@ -19,7 +19,6 @@ package com.zaxxer.hikari.proxy;
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.concurrent.ScheduledExecutorService;
 
 import com.zaxxer.hikari.pool.PoolBagEntry;
 
@@ -38,14 +37,6 @@ public interface IHikariConnectionProxy extends Connection
     */
    PoolBagEntry getPoolBagEntry();
 
-   /**
-    * Catpure the stack and start leak detection.
-    *
-    * @param leakThreshold the number of milliseconds before a leak is reported
-    * @param houseKeepingExecutorService the executor service to run the leak detection task with
-    */
-   void captureStack(long leakThreshold, ScheduledExecutorService houseKeepingExecutorService);
-
    /**
     * Check if the provided SQLException contains a SQLSTATE that indicates
     * a disconnection from the server.
@@ -55,27 +46,6 @@ public interface IHikariConnectionProxy extends Connection
     */
    SQLException checkException(SQLException sqle);
 
-   /**
-    * Get the expiration timestamp of the connection.
-    *
-    * @return the expiration timestamp, or Long.MAX_VALUE if there is no maximum lifetime
-    */
-   long getExpirationTime();
-
-   /**
-    * Get the last access timestamp of the connection.
-    *
-    * @return the last access timestamp
-    */
-   long getLastAccess();
-
-   /**
-    * Get the timestamp of when the connection was removed from the pool for use.
-    *
-    * @return the timestamp the connection started to be used in the most recent request
-    */
-   long getLastOpenTime();
-
    /**
     * Return the broken state of the connection.  If checkException() detected
     * a broken connection, this method will return true, otherwise false.

hikaricp-java6/src/main/java/com/zaxxer/hikari/proxy/LeakTask.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Brett Wooldridge
+ * Copyright (C) 2013, 2014 Brett Wooldridge
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,20 +16,36 @@
 
 package com.zaxxer.hikari.proxy;
 
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+
 import org.slf4j.LoggerFactory;
 
 /**
+ * A Runnable that is scheduled in the future to report leaks.  The ScheduledFuture is
+ * cancelled if the connection is closed before the leak time expires.
+ *
  * @author Brett Wooldridge
  */
-class LeakTask implements Runnable
+public class LeakTask implements Runnable
 {
    private final long leakTime;
+   private final ScheduledFuture<?> scheduledFuture;
    private StackTraceElement[] stackTrace;
 
-   public LeakTask(StackTraceElement[] stackTrace, long leakDetectionThreshold)
+   public LeakTask()
    {
-      this.stackTrace = stackTrace;
+      leakTime = 0;
+      scheduledFuture = null;
+   }
+
+   public LeakTask(final long leakDetectionThreshold, final ScheduledExecutorService executorService)
+   {
+      this.stackTrace = Thread.currentThread().getStackTrace();
+      
       this.leakTime = System.currentTimeMillis() + leakDetectionThreshold;
+      scheduledFuture = executorService.schedule(this, leakDetectionThreshold, TimeUnit.MILLISECONDS);
    }
 
    /** {@inheritDoc} */
@@ -37,8 +53,11 @@ class LeakTask implements Runnable
    public void run()
    {
       if (System.currentTimeMillis() > leakTime) {
+         StackTraceElement[] trace = new StackTraceElement[stackTrace.length - 3];
+         System.arraycopy(stackTrace, 4, trace, 0, trace.length);
+
          Exception e = new Exception();
-         e.setStackTrace(stackTrace);
+         e.setStackTrace(trace);
          LoggerFactory.getLogger(LeakTask.class).warn("Connection leak detection triggered, stack trace follows", e);
          stackTrace = null;
       }
@@ -47,5 +66,8 @@ class LeakTask implements Runnable
    public void cancel()
    {
       stackTrace = null;
+      if (scheduledFuture != null) {
+         scheduledFuture.cancel(false);
+      }
    }
 }

hikaricp-java6/src/main/java/com/zaxxer/hikari/proxy/ProxyFactory.java

@@ -42,9 +42,10 @@ public final class ProxyFactory
     *
     * @param pool the {@link HikariPool} that will own this proxy
     * @param bagEntry the PoolBagEntry entry for this proxy
+    * @param leakTask a leak detetection task
     * @return a proxy that wraps the specified {@link Connection}
     */
-   public static IHikariConnectionProxy getProxyConnection(final HikariPool pool, final PoolBagEntry bagEntry)
+   public static IHikariConnectionProxy getProxyConnection(final HikariPool pool, final PoolBagEntry bagEntry, final LeakTask leakTask)
    {
       // Body is injected by JavassistProxyFactory
       return null;

hikaricp/src/main/java/com/zaxxer/hikari/pool/HikariPool.java

@@ -47,6 +47,7 @@ import com.zaxxer.hikari.metrics.IMetricsTracker.MetricsContext;
 import com.zaxxer.hikari.metrics.MetricsFactory;
 import com.zaxxer.hikari.metrics.MetricsTracker;
 import com.zaxxer.hikari.proxy.IHikariConnectionProxy;
+import com.zaxxer.hikari.proxy.LeakTask;
 import com.zaxxer.hikari.proxy.ProxyFactory;
 import com.zaxxer.hikari.util.ConcurrentBag;
 import com.zaxxer.hikari.util.ConcurrentBag.IBagStateListener;
@@ -63,12 +64,13 @@ import com.zaxxer.hikari.util.PropertyBeanSetter;
  */
 public final class HikariPool implements HikariPoolMBean, IBagStateListener
 {
-   private static final Logger LOGGER = LoggerFactory.getLogger(HikariPool.class);
+   private static final Logger LOGGER;
+   private static final LeakTask NO_LEAK;
 
-   public int transactionIsolation;
    public final String catalog;
    public final boolean isAutoCommit;
    public final boolean isReadOnly;
+   public int transactionIsolation;
 
    private final DataSource dataSource;
 
@@ -94,6 +96,14 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
    private volatile long connectionTimeout;
    private volatile boolean isShutdown;
 
+   // static initializer
+   static {
+      LOGGER = LoggerFactory.getLogger(HikariPool.class);
+      NO_LEAK = new LeakTask() {
+         public void cancel() {};
+      };
+   }
+
    /**
     * Construct a HikariPool with the specified configuration.
     *
@@ -178,11 +188,9 @@ public final class HikariPool implements HikariPoolMBean, IBagStateListener
                continue;
             }
 
-            final IHikariConnectionProxy proxyConnection = ProxyFactory.getProxyConnection(this, bagEntry);
+            LeakTask leakTask = (leakDetectionThreshold == 0) ? NO_LEAK : new LeakTask(leakDetectionThreshold, houseKeepingExecutorService);
-
+            
-            if (leakDetectionThreshold != 0) {
+            final IHikariConnectionProxy proxyConnection = ProxyFactory.getProxyConnection(this, bagEntry, leakTask);
-               proxyConnection.captureStack(leakDetectionThreshold, houseKeepingExecutorService);
-            }
 
             if (isRecordMetrics) {
                bagEntry.lastOpenTime = now;

hikaricp/src/main/java/com/zaxxer/hikari/proxy/ConnectionProxy.java

@@ -24,8 +24,6 @@ import java.sql.Statement;
 import java.sql.Wrapper;
 import java.util.HashSet;
 import java.util.Set;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -41,27 +39,28 @@ import com.zaxxer.hikari.util.FastList;
  */
 public abstract class ConnectionProxy implements IHikariConnectionProxy
 {
-   private static final Logger LOGGER = LoggerFactory.getLogger(ConnectionProxy.class);
+   private static final Logger LOGGER;
-
    private static final Set<String> SQL_ERRORS;
 
    protected final Connection delegate;
 
    private final HikariPool parentPool;
    private final PoolBagEntry bagEntry;
-
+   private final FastList<Statement> openStatements;
+   private final LeakTask leakTask;
+   
    private boolean forceClose;
+   private boolean isAnythingDirty;
    private boolean isAutoCommitDirty;
    private boolean isCatalogDirty;
    private boolean isClosed;
    private boolean isReadOnlyDirty;
    private boolean isTransactionIsolationDirty;
 
-   private FastList<Statement> openStatements;
-   private LeakTask leakTask;
-
    // static initializer
    static {
+      LOGGER = LoggerFactory.getLogger(ConnectionProxy.class);
+
       SQL_ERRORS = new HashSet<String>();
       SQL_ERRORS.add("57P01"); // ADMIN SHUTDOWN
       SQL_ERRORS.add("57P02"); // CRASH SHUTDOWN
@@ -71,10 +70,11 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       SQL_ERRORS.add("JZ0C1"); // Sybase disconnect error
    }
 
-   protected ConnectionProxy(final HikariPool pool, final PoolBagEntry bagEntry) {
+   protected ConnectionProxy(final HikariPool pool, final PoolBagEntry bagEntry, final LeakTask leakTask) {
       this.parentPool = pool;
       this.bagEntry = bagEntry;
       this.delegate = bagEntry.connection;
+      this.leakTask = leakTask;
 
       this.openStatements = new FastList<Statement>(Statement.class, 16);
    }
@@ -96,18 +96,6 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       return bagEntry;
    }
 
-   /** {@inheritDoc} */
-   @Override
-   public final void captureStack(long leakDetectionThreshold, ScheduledExecutorService executorService)
-   {
-      StackTraceElement[] trace = Thread.currentThread().getStackTrace();
-      StackTraceElement[] leakTrace = new StackTraceElement[trace.length - 4];
-      System.arraycopy(trace, 4, leakTrace, 0, leakTrace.length);
-
-      leakTask = new LeakTask(leakTrace, leakDetectionThreshold);
-      executorService.schedule(leakTask, leakDetectionThreshold, TimeUnit.MILLISECONDS);
-   }
-
    /** {@inheritDoc} */
    @Override
    public final SQLException checkException(SQLException sqle)
@@ -184,8 +172,6 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       if (isCatalogDirty && parentPool.catalog != null) {
          delegate.setCatalog(parentPool.catalog);
       }
-
-      delegate.clearWarnings();
    }
 
    // **********************************************************************
@@ -199,10 +185,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       if (!isClosed) {
          isClosed = true;
 
-         if (leakTask != null) {
+         leakTask.cancel();
-            leakTask.cancel();
-            leakTask = null;
-         }
 
          try {
             final int size = openStatements.size();
@@ -216,10 +199,14 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
                   }
                }
 
-               openStatements = null;
+               openStatements.clear();
+            }
+
+            if (isAnythingDirty) {
+               resetConnectionState();
             }
 
-            resetConnectionState();
+            delegate.clearWarnings();
          }
          catch (SQLException e) {
             throw checkException(e);
@@ -432,6 +419,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setAutoCommit(autoCommit);
+         isAnythingDirty = true;
          isAutoCommitDirty = (autoCommit != parentPool.isAutoCommit);
       }
       catch (SQLException e) {
@@ -446,6 +434,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setReadOnly(readOnly);
+         isAnythingDirty = true;
          isReadOnlyDirty = (readOnly != parentPool.isReadOnly);
       }
       catch (SQLException e) {
@@ -460,6 +449,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setTransactionIsolation(level);
+         isAnythingDirty = true;
          isTransactionIsolationDirty = (level != parentPool.transactionIsolation);
       }
       catch (SQLException e) {
@@ -473,6 +463,7 @@ public abstract class ConnectionProxy implements IHikariConnectionProxy
       checkClosed();
       try {
          delegate.setCatalog(catalog);
+         isAnythingDirty = true;
          isCatalogDirty = (catalog != null && !catalog.equals(parentPool.catalog)) || (catalog == null && parentPool.catalog != null);
       }
       catch (SQLException e) {

hikaricp/src/main/java/com/zaxxer/hikari/proxy/IHikariConnectionProxy.java

@@ -19,7 +19,6 @@ package com.zaxxer.hikari.proxy;
 import java.sql.Connection;
 import java.sql.SQLException;
 import java.sql.Statement;
-import java.util.concurrent.ScheduledExecutorService;
 
 import com.zaxxer.hikari.pool.PoolBagEntry;
 
@@ -38,14 +37,6 @@ public interface IHikariConnectionProxy extends Connection
     */
    PoolBagEntry getPoolBagEntry();
 
-   /**
-    * Catpure the stack and start leak detection.
-    *
-    * @param leakThreshold the number of milliseconds before a leak is reported
-    * @param houseKeepingExecutorService the executor service to run the leak detection task with
-    */
-   void captureStack(long leakThreshold, ScheduledExecutorService houseKeepingExecutorService);
-
    /**
     * Check if the provided SQLException contains a SQLSTATE that indicates
     * a disconnection from the server.

hikaricp/src/main/java/com/zaxxer/hikari/proxy/LeakTask.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2013 Brett Wooldridge
+ * Copyright (C) 2013, 2014 Brett Wooldridge
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,20 +16,36 @@
 
 package com.zaxxer.hikari.proxy;
 
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.ScheduledFuture;
+import java.util.concurrent.TimeUnit;
+
 import org.slf4j.LoggerFactory;
 
 /**
+ * A Runnable that is scheduled in the future to report leaks.  The ScheduledFuture is
+ * cancelled if the connection is closed before the leak time expires.
+ *
  * @author Brett Wooldridge
  */
-class LeakTask implements Runnable
+public class LeakTask implements Runnable
 {
    private final long leakTime;
+   private final ScheduledFuture<?> scheduledFuture;
    private StackTraceElement[] stackTrace;
 
-   public LeakTask(StackTraceElement[] stackTrace, long leakDetectionThreshold)
+   public LeakTask()
    {
-      this.stackTrace = stackTrace;
+      leakTime = 0;
+      scheduledFuture = null;
+   }
+
+   public LeakTask(final long leakDetectionThreshold, final ScheduledExecutorService executorService)
+   {
+      this.stackTrace = Thread.currentThread().getStackTrace();
+      
       this.leakTime = System.currentTimeMillis() + leakDetectionThreshold;
+      scheduledFuture = executorService.schedule(this, leakDetectionThreshold, TimeUnit.MILLISECONDS);
    }
 
    /** {@inheritDoc} */
@@ -37,8 +53,11 @@ class LeakTask implements Runnable
    public void run()
    {
       if (System.currentTimeMillis() > leakTime) {
+         StackTraceElement[] trace = new StackTraceElement[stackTrace.length - 3];
+         System.arraycopy(stackTrace, 4, trace, 0, trace.length);
+
          Exception e = new Exception();
-         e.setStackTrace(stackTrace);
+         e.setStackTrace(trace);
          LoggerFactory.getLogger(LeakTask.class).warn("Connection leak detection triggered, stack trace follows", e);
          stackTrace = null;
       }
@@ -47,5 +66,8 @@ class LeakTask implements Runnable
    public void cancel()
    {
       stackTrace = null;
+      if (scheduledFuture != null) {
+         scheduledFuture.cancel(false);
+      }
    }
 }

hikaricp/src/main/java/com/zaxxer/hikari/proxy/ProxyFactory.java

@@ -42,9 +42,10 @@ public final class ProxyFactory
     *
     * @param pool the {@link HikariPool} that will own this proxy
     * @param bagEntry the PoolBagEntry entry for this proxy
+    * @param leakTask a leak detetection task
     * @return a proxy that wraps the specified {@link Connection}
     */
-   public static IHikariConnectionProxy getProxyConnection(final HikariPool pool, final PoolBagEntry bagEntry)
+   public static IHikariConnectionProxy getProxyConnection(final HikariPool pool, final PoolBagEntry bagEntry, final LeakTask leakTask)
    {
       // Body is injected by JavassistProxyFactory
       return null;